Simply put, Content Managment takes many decisions about your web content out of your designers or IT department's hands, and puts it back in yours. It allows you to create/add/delete content from your site without needing code. In fact, the article you're reading right now was written in Actin's content management interface, which looks a lot like a standard word processing program. Ours is online, meaning that you can login to your site's "backend" interface and publish directly to your site. Or if you prefer you can write it in the word processing program of your choice and simply paste it into your CM backend.

Content Managment also allows for various permission levels. You can give different individuals author, editor, or admin permissions to be sure that your content management system stays managed. You can also define the permissions of your site's end users, having some pages that are internal, others external to registered customers, and others that can be seen by the general public.